# Internal resistance of the cell

Internal resistance in simple words means the electrical resistance inside the batteries and also in the power supplies which can limit the potential difference that can be supplied to external this is caused when there is current or electric circuits are there in the device or there can be a voltage drop or source battery can be internal resistance. Another cause of this is a material called electrolytic present in batteries. This is important because it is considered to get the source to be delivered maximum power to an electrical appliance and it allows high currents to be stable and not falling significantly. The unit for internal resistance is an electromotive force or called EMF.

## What is an electromotive force and how this is important?

Electromotive forces measured in volts and EMF is the derivation used for it and this is known as electrical action produced by non-electrical source. In other words, EMF can be defined as a closed loop of the conductor as the electromagnetic work which can be done on an electric charge. Some examples of the device which can provide EMF are an electrochemical cell, thermoelectric devices, solar cell, electrical generators, transformers, and photodiodes. Another definition for this EMF can be an electrical voltage difference. EMF plays a crucial role in the development of new power energy such as solar cells, transformer, and voltaic cells. It also includes electromagnetic induction which means a time-dependent magnetic which produced a calculated field or it can be produced either by the motion of a magnet relative to a circuit or by changing the current in the fixed circuit. In this whole scenario, EMF is determined by the rate of change of magnetic flux through the circuit.

## Combination of cells.

There are two types of combination by which a cell can be arranged first is by series or second is by parallel. Cell are connected by series when they are joined from end to end which makes the same quality of electricity flow through each cell by this the current in each cell is the same and can be identified by the current in the arrangement. One reason to connect them in series is when the internal resistance is negligible in comparison with the cell which are external and to get maximum current. On another hand cell are connected parallel only when they are joined positive to positive and negative to negative so that current can be divided between the cell.